Getting WooCommerce Cart Subtotal

gistfile1.php

<?php

add_action('woocommerce_cart_updated', 'growdev_woocommerce_cart_updated', 90);
function growdev_woocommerce_cart_updated ( $cart ){

	// output subtotal
	error_log( "subtotal: " . WC()->cart->subtotal  );

	// output the
	error_log( "get_cart_subtotal: " . WC()->cart->get_cart_subtotal() );
}